Design Methods Flexible, Rigid & Composite CBR Method Asphalt Institute method National Crushed Stone Association Design Method California Method AASHTO Method Mechanistic design Method

Design of Overlays An overlay is one or more courses of asphalt or Portland cement concrete construction on an existing pavement. The overlay generally includes a levelling course to correct the contour of the old pavement, followed by uniform course or courses to provide needed thickness. Importance of Overlay Most overlay design procedures however can be categorized into:  Component analysis  Deflection-based analysis  Analytical or Mechanistic-based procedures

Pavement maintenance & Rehabilitation The current AASHTO definition of highway maintenance is: A programme to preserve, repair and restore a system of roadway with its element to its designated or accepted configuration. System elements include travel way surfaces, shoulders, roadsides, drainage facilities, bridges, tunnels, signs, markings, lighting fixtures, etc. Included in the programme are such traffic services as lighting and signal operations, snow and ice removal, and operation of roadside rest areas. Rehabilitation encompasses overlays, recycling, reconstruction and their combinations.

Pavement distress Distress is defined as an indication of unfavourable pavement performance or signs of impending failure, or any unsatisfactory performance of pavement short of failure.  Distress types in flexible pavements- Cracking, Distortion, Disintegration, Skid hazard  Distress types in rigid pavements- Joints and cracks, Distortion, etc.